In the semiconductor industry, devices are fabricated by a number of manufacturing processes producing structures of an ever-decreasing size. Some manufacturing processes such as plasma etch and plasma clean processes expose a substrate support such as an electrostatic chuck (ESC) (e.g., an edge of ESC during wafer processing and the full ESC during chamber cleaning) to a high-speed stream of plasma to etch or clean the substrate. The plasma may be highly corrosive, and may corrode processing chambers and other surfaces that are exposed to the plasma.
An ESC typically has surface features that are created by placing a positive mask on a surface of the ESC and then bead blasting exposed portions of the ESC through the positive mask. The positive mask is a mask that contains an exact copy of the pattern which is to remain on the wafer. The bead blasting process causes sharp edges and cracking in the ESC surface. Additionally, the spaces between formed surface features (referred to as valleys) have a high roughness that provides traps that trap particles and peaks that can break during thermal expansion. The trapped particles and broken peaks can cause particle contamination on the backsides of wafers that are held during processing.